Hacking has been on house-hunting hiatus. Now I am back.
After hearing back from RepRapFab.de which part would come apart, I unscrewed the bottom of the extruder. The power resistor is fine (though the glue has come out a bit, but there's a distinct lack of thermistor. Need to drop by Conrad (Heißleiter S861 Epcos HEISSLEITER, PRÄZ.TEMP.-MESSUNG, S861, Bestell-Nr.: 500682 - 62), they have some. Also need to get glue, suggested is JB Weld.
In the meanwhile, I can test the motors. First installing software according to https://github.com/nophead/Marlin:
- Download Arduino IDE v22. No such thing, their numbers go 1.0.N, 1.5.N, 1.6.N. I have 1.5.8 which I updated for the ATTiny programming. But then that page was last updated 3 years ago. Which means... he's talking about 0.22. From February 2011. I sure hope it's upwards compatible.
- This is neither gen6 or Sanguinololu, skip.
- UltiMaker's RepG 25 build. That could either ReplicatorG which comes in versions 23 and 34 but nothing in between, or UltiReplicatorG which does come in a version 25 (see http://software.ultimaker.com/?show=all). Going with URG because that was the newest version in Nov. 2011 when that part was written.
- UltiMaker Marlin firmware has moved, tree/v_1 is gone, but tree/Stable/Marlin is probably ok. Unfortunately, there is no download button, there, only at the root dir. Oh, look, this is EricZahn's Marlin, not nophead's. I'll go with nophead's, not because it's more fixed necessarily, but because it's more likely to have fixes for Mendel90. Based on earlier Arduino experience, placed in in ~larsrc/Documents/Arduino.
Oh, the Melzi uses MiniUSB rather than USB-B of the Arduino. Fortunately, FabLab does have a collection of every imaginable USB cable, plus a few I hadn't seen before.
Powering it up and connecting it has less effect than I hoped for. Shouldn't there at least be a single Blinkenlicht? The PSU is nice and quite, I had to feel the air from the fan to check that it was on.
No Melzi appears in the Arduino menu. My earlier Arduino experience was misremembered. It needs to be in ~larsrc/Documents/Arduino/hardware. There you are, little puppet! Actually, there two of you are. Which one do I have? Android Cozy Magnifier app to the rescue, it's an ATMega1284.
There is power on the Melzi, as measured at the yellow and black cables. The dummy 5V load is also active.
Have to do some testing on my own, since the manual just says "comes with test firmware". This is fortunately where Arduino rocks: The same program I used yesterday to make my ATTiny programmer blink can be used here with merely adapting the pin number. Nice little test, aaand...
Third-party platform.txt does not define compiler.path. Please report this to the third-party hardware maintainer.
Ran into this yesterday, too. Then, I just had to change a line in platforms.txt, but the Melzi doesn't come with one of those.
Ah, but the Marlin instructions said to open Marlin.pde in Ardiuno and compile that. Not that the Marlin download comes with one of those. There's Marlin.ino, let's try that just for shits and giggles. Still complains about the compiler.path, and then dies with a RunnerException.
Noticed the Mendel90 instructions talk about a Marlin/Marlin/Marlin (!) dir. Maybe that's expected somewhere, trying to move it into that configuration. Oh, look, a new error message:
In file included from Marlin.h:24:0,
fastio.h:2579:2: error: #error pins for this chip not defined in arduino.h! If you write an appropriate pin definition and have this firmware work on your chip, please submit a pull request
Also, the Melzi doesn't turn up in the boards menu any more:(
Tried installing an Arduino 1.0.5. It doesn't recognize the Melzi drivers at all. Tried copying a platforms.txt into the Arduino app's config files, no go. But copying it into ~larsrc/Documents/Arduino/... worked! The firmware now compiles.
Next up: Uploading. Selected Melzi, picked the tty USB port, and don't really know if the Programmer setting makes a difference here, so I tried them all, and for all got a "missing upload.tool" error.
Found a GitHub issue about this, which seems to indicate that upload.tool and bootloader.tool should be set to avrdude or some other default value. Added them as avrdude (dude!), to get by this error.
I don't even know if my ATMega came blank. Ah, the joys of self-sourcing.
There's no section on installing the software on a mac in the manual, only Windows and Linux. Fortunately, the Linux instructions seem similar enough to what I had to do for the Arduino, so I'm pretty sure it works.
Maybe the USB cable I dug up was bad? Trying a different one, and switching the mains power jump back and forth, indeed got a light to shine! And it even succeeds in uploading! Though the light goes out again after that. That seems to be a function of the firmward, the blink program blinks happily.
Installed Pronterface (Printrun) and started it. It immediately went into shutdown because the extruder temperature was too low (missing thermistor, duh!). By adding a 65K resistor across the thermistor inputs, I fooled it into running and could do basic movement tests.
X axis: Moves, homes nicely (with my little hack), but refuses to go more than halfway across for no obvious reason.
Y axis: Works beautifully.
Z axis: Moves, but rather jumpily. When homing, it stopped almost at the top, and now it refuses to go downwards again. I may have to switch direction of the Z endstop to have it hit in time.
Bed: Heats up nicely.
Extruder: Can't test yet, not wired.
Part of the Z problem and all of the X problem turned out to be the hex nut on the threaded rod having come undone on the right side. This made the X axis slanted enough that the motor didn't like it. Fixing that, the motor moves nicely, but I still can't get down, there is too much resistance. Maybe I need to oil it.
Required reading: Arduino 3rd-party Hardware Specification.
Also, why does Arduino keep asking for incoming network connections? It has no business with that.